Posted
by
michael
on Thursday November 18, 2004 @11:23AM
from the moon-still-mostly-empty dept.

NuclearRampage writes "Technology Review has an in-depth article about A New Vision for Nuclear Waste based on the premise that 'storing nuclear waste underground at Yucca Mountain for 100,000 years is a terrible idea.' The article looks at the current DOE plans for Yucca, its shortcomings and what temporary solutions we have to use while a better permanent plan is formulated."

Why not just press for reprocessing of spent fuel? All the 250,000 year stuff is from material that can be recovered back into the fuel cycle. If you remove the junk lower down on the periodic table (the real nuclear waste) it only will be dangerous for a few hundred years.

On a side note, has anyone heard of the natural reactor in Oklo [wikipedia.org]? A naturally occurring nuclear reaction there produced all the same waste of a modern reactor and it all stayed in place in de-facto geologic storage.

yucca is ready to accept waste, vitrification [wikipedia.org] is mature. I really don't see why Yucca is still a controversy other than NIMBY and ignorance.

If the waster is radioactive, it is inherently releasing energy. I have never understood why no one has tried to take advantage of this with some kind of "dirty" reactor.

The problem is that the fuel has been "poisoned" by decay products from previous reactions. Enough of these absorb neutrons that you can't sustain a critical fission reaction, and so you're left with sub-critical decay. This gives off energy, but far, far more slowly than a nuclear plant's active fuel bundles do. So you can't put them in a conventional reactor, and you can't get useful amounts of heat off them outside of one.

There are some types of reactor - actinide-burning fast-breeders - that have less trouble with these decay products than conventional slow-neutron reactors. These are widely viewed as one method of disposing of or at least reducing the amount of spent fuel waste. You can also chemically reprocess the fuel to remove the decay products (which are then disposed of as waste, but the majority of your "spent" fuel is reused). Neither of these solutions is allowed in the US, due to proliferation risks and handling concerns.

Actually grinding it into fine particulates and releasing it into the atmosphere would be a very bad thing as inhaling fine radioactive dusts (or gases) is, apart from extreme rad exposure, one of the fastest ways to get killed by radiation.

Not to mention the fact that the stuff would settle on cropping regions and build up in the surface soil and the oceans, thus contaminating food sources (living cells have a tendancy to accumulate heavy metals). Essentially what you would create is fallout.

(This article originally appeared in DIE ZEIT, 32/2004 http://zeus.zeit.de/text/2004/32/Kernenergie and has been translated from German.)

Nuclear energy is still too expensive and too dangerous. Huge amounts of water are needed in a time of increasing water shortage. Uranium supplies are limited. In Europe $1 trillion was spent on nuclear research while renewable energy fell by the wayside.

The end of the fossil energy age approaches. Its ecological limits draw near as material resources are exhausted. The advocates of nuclear energy see a new day dawning. Even some of its critics have joined the appeal for new nuclear power plants. 442 nuclear reactors are now operating worldwide with a total capacity of 300,000 Megawatts. Two and a half times this number will be added by 2030 and four times as many by 2050, says the International Atomic Energy Agency (IAEA), the bastion of the global nuclear community.This pro-nuclear argument relies on twofold inhibition. Amid contrary facts, the economic advantages are praised. The risks are minimized or declared technically surmountable. At the same time, renewable energies are denounced as uneconomical, with their potential marginalized in order to underscore the indispensability of nuclear energy.

Trivializing the reactor catastrophe at Chernobyl is part of this strategy. In DIE ZEIT 31/2004, Gerd von Randow wrote that there have been only 40 deaths and 2000 registered cases of thyroid cancer. These figures have been provided by advocacy organizations. Independent studies, such as the report of the Munich Radiation Institute, have identified 70,000 casualties that include desperate suicides and the tens of thousands of long-term victims additionally projected.

Comparing these victims with the victims of coal mining and fossil energy emissions is an element of minimization. However, both the massive nuclear and fossil tragedies necessitate mobilizing renewable energy as the only prospect for lasting, emission-free, benign, and inexpensive supplies.

The deployment of nuclear energy is the result of gigantic mechanisms of subsidization and privilege. Before 1973, OECD governments spent over $150 billion (adjusted to current costs) in researching and developing nuclear energy, and practically nothing for renewable energy. Between 1974 and 1992, $168 billion was spent on nuclear energy and only $22 billion on renewables. The European Union's extravagant nuclear promotion efforts are not even included in this calculation. French statistics are still being kept secret. The total state support amounts to at least a trillion dollars, with mammoth assistance provided to market creation and to incentives for non-OECD countries, above all the former Soviet block.Only $50 billion has been spent on renewable energy. Since 1957, the IAEA and Euratom have assisted governments in designing nuclear programs. By contrast, no international organizations exist today for renewable energy.

After the middle of the seventies, nuclear energy was largely burnt out, due more to enormously increased costs than to growing public resistance. The limitations on construction have become more severe. Uranium reserves estimated at a maximum 60 years refer to the number of plants currently in operation. With twice the number, the available time periods would inevitably be cut in half. The expansion calculated by the IAEA could not be realized without an immediate transition to the fast breeders for extending the uranium reserves!

The history of the breeder reactors is a history of fiascos. Like the Russian reactor, the British reactor achieved an operating capacity of 15 percent before its shutdown in 1992. The French Super Phoenix (1200 Megawatts) attained 7 percent and cost 10 billion euros. The much smaller Japanese breeder (300 Megawatts) cost 5 billion euros and experiences regular operating problems. Making these reactors fit for operation, if that were to prove possible

It's an appealing idea, but suffers from the slight problem of being completely wrong.

Indeed, natural uranium in the ground is really not very hazardous -- U235 is the most radioactive isotope, but is only a very small percentage of natural uranium and has a half-life of many millions of years. It's so benign that it was used as a pigment in early Fiesta Ware dishes and blue-blocker optical components (admittedly, it is not quite benign enough for these purposes...these have been recalled, but it's close.)

But, nuclear fission creates a spectacular kaleidescope of new isotopes. These are hundreds of thousands of times more radioactive than the natural uranium that was in the ground. It's true that they will only be extremely dangerous for a limited time, but that limited time is still in the many thousands of years.

While just reburying nuclear waste has some naive (although as show above, wrong) appeal, releasing them to the atmosphere is completely insane. This has been done already, in Chernobyl, on a relatively small scale. The area around the plant will be uninhabitable for a few thousand years.

Read the article. It's remarkably good, and makes a good case for temporary "cask" storage for a hundred years or so. There is little that you can say for certain about the future, but the one thing you can say is that it will be very different than the present, and different in unforseeable ways.

If you're really ambitious, read the Yucca Mountain reports from the goverment, available at John Young's indispensible cryptome.org [cryptome.org] among other places. The documents are amazingly detailed and well researched, and describe the truly monumental efforts proposed to make the best of the sadly misguided site that is Yucca Mountain. Radical alloys, glass matrices to bind the material, titanium drip shields, it just goes on and on and on. (The word "monumental" is actually literal, not just figurative. Part of the proposal describes the need for monuments to warn people away from the site for the next 10,000 years.)

The engineers and scientists working on Yucca Mountain were given the task to keep the amount of radiation leaking out of the site to low levels for 10,000 years. If everything goes exactly right, if there are no unforseen events, and the experimental materials they are using perform exactly as predicted under high radiation and hydrological stress for that time, the site will meet that mission. Astonishingly, the radiation release graphs go off the chart after 10,000 years -- there's still enough radiation there after that time to be terribly dangerous, and all protective measures will hae failed by that point.

Yucca Mountain was chosen and designed based on the assumption that it was dry. It's wet. That's such a huge difference that the original decision was simply wrong.

Getting the waste out of Earth's gravitational well takes MORE energy than the radioactive materials generated in the first place.

Never mind the dangers of rocket exploding on launch. I know!How about making it safe for launch by making a huge block of (diluted) glass or cement - and vastly increasing the weight that has to be launched out of Earth's gravity well?

Subduction zones are typically under the ocean, and you still have to dig over a kilometer down from the bottom of the ocean to reach the mantle

This is so far beyond our current technology that making a winged monkey sounds easy in comparason.

And anyways, if you learned your basic geology, you'd know that above every subduction zone is a large range of volcanoes that eject a large amount of the melted magma that goes down in the subduction zone- can you imagine a mount st. helen's type eruption, except with radioactive dust spewing out?

And about putting it in the middle of the desert, how is that any different from yucca mountain? At least the mountain will be sheltered from the elements, be much easier to guard against, and can be permanantly sealed off if the government doesn't want to pay for armed guards.

It's not going downhill towards the Sun that costs too much. It's going uphill from Earth that makes it impraticable.

Orbital speed near the earth's surface is sqrt(gr)=7745 m/s. The escape velocity is sqrt(2) times that, or 11 km/s.

Orbital velocity around the sun is about 30 km/s. Neglecting the radius of the sun itself, you'd have to burn enough rocket fuel to reach 30 km/s relative to the earth to get rid of your angular momentum relative to the sun. Getting it off the earth would be the easy part.

Getting it out of the solar system (past Pluto) would be easier than getting it to the sun. Escape velocity at Earth's orbit is sqrt(2)*30 or 42 km/s, only 42-30=12 km/s of a difference from the waste's speed on the ground, which is still greater than the 11 km/s required to escape Earth.

First, after several tens of years, the composition of fuel rods changes significantly -- the shorter-lived components will decay and the waste will generate far less heat. The ideal storage environment changes substantially then.

Also our current waste-management techology is immature, and not proven to be good enough. But a few new developments are on the horizon.

Future technology is likely to make fuel reprocessing more economic (and I think he did this without even mentioning breeder reactors).

Finally, the Yucca mountain storage facility is gridlocked in politics and thus not a realistic short-term option.

Then the author addresses your question, and suggests using our present temporary solution of casques but upgrading it to a centralized facility that can be hardened against terrorist abuses. It's not clear to me that this is the best way to go but it's obvious that we need an *immediate* improvement over what we're doing now, and that we really want to consider a temporary storage technology that's good for 100-200 years, not necsessarily 100-200 thousand years.

Yeah, I really want to use a reactor that uses *Liquid Sodium* as coolant (that fact alone made them incredibly hard beasts to work with - it reaks havoc on the pumps). There's still research going on to make more economically viable and technologically realistic breeder reactors, but as for now, the tech just isn't there.

The real problem with Yucca Mountain is the water table issue and the fact that most of these waste materials are extremely toxic. Nuclear reactors do not produce large amounts of isotopes "hundreds of thousands of times more radioactive" than "natural" uranium. And if they did, the half-life for them would be extremely short. The reason it takes millions of years for these waste materials to become functionally inert is because they are alpha emitters with very long half-lives. In other words, they do not produce large amounts of dangerous radiation. As they decay they will hit stages of greater radiation, but remember, alpha particles cannot even penetrate the layer of dead skin cells covering our bodies. A sheet of paper is strong enough shielding. Beta emmiters are somewhat more dangerous, but not significantly so. Additionally, while alpha particle radiation can still cause mutagenic aberrations if it can get passed your clothes and skin; the real danger is application to an open wound, inhalation, or ingestion of the radioactive materials. Not only does this allow the alpha particles to damage sensitive internal organ tissue, but the materials themselves are highly toxic. This is one of the reasons that radon (the end product of the uranium in the earth naturally decaying) in our basements is such a concern. Radon being gaseous enters our lungs where the alpha particles can actually do damage.

Chernobyl's problem was not the release of radiation into the atmosphere. That is disapated very rapidly by prevailing winds and does not affect the surrounding area significantly (not from a single event such as that). The problem with Chernobyl was that when the top blew chunks of radioactive debris like pieces of the graphite cooling system rained down over the surrounding countryside and got into the ground and the water supply.

Most of the deaths in Nagasaki and Hiroshima [atomicarchive.com] were caused by the shockwave and the subsequent fires, not the radiation. This is not to say that there weren't many people killed by radiation, there were. But those individuals dying of cancer caused by those blasts are the individuals that were present at the time of the attacks. Both areas are still thickly settled and do not have higher than normal cancer rates outside of the population of the bomb drop survivors.

Additionally, far larger amounts of the same materials used and produced in nuclear power production (including uranium 235, uranium 238, and thorium among others) are pumped into our atmosphere every day by coal burning plants [ornl.gov]. In fact, if we took all the radioactive materials we send into the air every year and put them in nuclear reactors, we'd be able to make more energy that the coal plants that put them into the atmosphere did during the same timeframe.

On top of that, if breeder and pellet based plutonium reactors were actual in service we could use the waste from standard light water reactors to feed breeder reactors whose waste would feed the pellet based reactors. Drastically reducing the amount and lethality of the nuclear waste that we'd ultimately have to store.

The main reason we're having such problems with nuclear waste repositories such as Yucca mountain is because of the rather long timescales of decay of a small class of fission byproducts. This class of elements (the 'transuranics' ; Z > 92) comprises a very small fraction of the total waste volume and has (in general) the majority of ill-effects, such as long half-lives, toxicity, excessive heat generation, etc. (Different isotopes contribute to each of these effects in some small fashion.)

A key insight to the problem is that we do not have to store the waste as it comes out of the reactor (or otherwise packaged for long-term storage). It is possible to process the spent fuel in a way to transmute the problem isotopes into others that decay away quickly (days to tens/hundreds of years vs 1x10^6 + years). Neutron bombardment is one method of 'bumping' these decay chains onto different tracks. Doing this effectively, efficiently, and economically is
the challenge; many people (including some of my professors) have been working on it at Los Alamos. A good introduction to the process and its rationale are located here [lanl.gov].

Of couse, these transmutation schemes require their own energy to run them, and we can't beat the second law of thermodynamics -- it has to come from somewhere. These days it's mostly coal, the same source we're trying to replace with nuclear power! (Don't get me wrong -- nuclear power plants are by far the best we've currently got in terms of environmental impact, reliability, and production capacity. It's not the best, but it's the least of the other evils at the moment.) A better solution would be to provide this energy from an environmentally clean source, such as fusion energy [iter.org]. (It's nice to see two nuclear physics articles in a day!)

Of course, providing funding for disposal solutions such as Yucca and transmutation technologies is expensive and a political hot potato. (It also requires members of Congress to be a bit more forward-sighted, instead of just looking ahead to the next election cycle. Just think: ITER is on the order of $10B [a drop in the bucket to Congress], and has been scrounging for funds from all across the world for more than 20 years -- when it has the potential to unlock safe, envirionmentally clean energy that's powered from constituents of seawater.)

I think he worded this poorly. The point is that taking the waste and immediately putting it in a high density facility is bad because it is releasing heat so fast -- apparently many problems with Yucca engineering are due to this high heat release. By having a lower density staging area you both solve this problem and allow time for the development of better long-term solutions.

This sounds like talking about solutions to me. One of his main points is that the Department of Energy is ignoring alternatives at all costs, that's why it seems like there are no other solutions.

His main point is that Yucca is taking so long that by default such a low density staging area is coming soon to a big field near you! Wouldn't it be better to do that all in one place far away from population centers?

And anyways, if you learned your basic geology, you'd know that above every subduction zone is a large range of volcanoes that eject a large amount of the melted magma that goes down in the subduction zone- can you imagine a mount st. helen's type eruption, except with radioactive dust spewing out?

Material takes millions of years to go from oceanic crust to pyroclastics spewing out of a volcano. The radioactivity would have decayed to innocuous levels by then anyway. I'm not saying that burying waste in a subduction zone is a good idea at all, though.

Storing nuclear waste at Yucca mountain may not be the best idea, or a great idea, it may even be a bad idea, but is it really a "terrible" idea? Or is saying it's a "terrible" idea one of those little pieces of hyperbole designed to subconsiously sway an argument.

As pointed out in the article and by another poster, the problem is that Yucca Mountain was selected because proponents thought that it's a dry place.

It's not. The ground is quite moist, and about a year ago (or two?), they found water leaking through the tunnels. The problem is that water will cause corrosion in the caskets that store the waste (again, as pointed out in the article).

Imagine that thousands of caskets are stored in a chamber, and water leaks through the chamber's ceiling. It intermixes with the caskets and carries away pieces of radioactive material. The water then escapes the facility through leaks in the floor of the chambers. That contaminated water then enters the ground water and eventually spreads through the ecosystem.

It's a disaster waiting to happen. 10,000 people every month are moving into the Las Vegas metropolitan area to live.

The average output per panel over an entire day is approximately 0.2kW per m^2. In other words, the sun provides direct light an average of six hours per day averaging 0.8kW per m^2 each of those six hours. I think that's a fair estimate.

Solar cells that are currently mass produced and have a reasonable lifetime (30 years or more) max out at about 15% efficiency. But I'll allow for incremental improvements if this was to roll out. Let's say 18% to be generous. 0.2kW/m^2 * 0.18 = 0.036kW/m^2.

Multiplying by 24 hours (since we already made an average based on the whole day) gives you 0.864kWh/m^2/day.

Multiply by 250 days (no place on the planet has 365 days of perfect sunshine, and yet I'm being generous) and you get 216kWh/year per sq. meter. Divide 3.848 trillion kWh by 216kWh per sq meter and you get 17,814,814,815 sq. meters. Divide by a million to get sq. kilometers. That comes to 17,815 square kilometers. Quick unit conversion leaves 6,878 square miles.

Now let's reflect. In this best case scenario where you have plenty of sunshine, better than the best mass produced cells available today, the cells are kept clean, no major earthquakes, no tornados, etc., you still need 6,878 square miles of the stuff. Last I looked, I see that a square meter panel costs about $500 -- and solar is federally subsidized! Even if you factor in economies of scale whereby subsidies are not necessary and street costs are slashed in half, you are talking about $4,453,703,703,704. Just so we're clear, that's $4.453 trillion dollars. Even if you reduced the price of panels by a factor of ten from what they are today, you are still talking about $800 billion. Also don't forget that this was a forgiving estimation.

More realistic estimates place the land necessary at 10,000 square kilometers and do no expect such huge drops in price. Remember, this would be a government contract. Nobody will be bidding particularly low.

And I haven't gotten to the best part yet. You have to replace a substantial amount of cells every thirty years or so as the cells wear out and are damaged (how do you protect thousands of square miles from acts of sabotage?). Oh yes, let's not forget that overall demand is increasing, not decreasing.

If this sounds reasonable to you, I think you have a problem with your brain not being screwed on tight.

Actually, I think I read about that previously. Interesting design, really:) Unfortunately on slashdot, if you say anything bad about any particular type of nuclear reactor, they assume you're some nuclear-hating nut.

Nuclear power has huge potential and huge risks. Some people (usually not on slashdot) like to pretend that the potential isn't there. Many on slashdot like to pretend that the risks (note: not mainly of death, but of ruining large amounts of valuable land for several hundred years) don't exist. One has to be objective and look at all the data. Data on current breeders isn't that great, unfortunately. That's why I really like to hear news about new breeder designs. Breeders could literally supply the world with power for several thousand years on known uranium reserves alone.

PBMRs are also really interesting, promising reactors, although the plans in many places to build them without containment structures are more than a little scary. For one, nuclear grade graphite *does* burn, as we saw in Chernobyl, in some circumstances - in fact, it was the burning nuclear grade graphite that was largely the problem when it came to radiological waste dispersion. Also, at the test reactor in Germany, they had some problems about pellets getting caught in the machinery (which were a big pain to get out), although I'm sure things like that can be resolved, and you're not going to be at a risk for radiological dispersal from such accidents (just economic loss from downtime and repair).

Here's a page with a quick summary on an LFR (Lead-cooled Fast Reactor):

http://energy.inel.gov/gen-iv/lfr.shtml

The Russian one is called BREST; it's also an anti-proliferation design:

http://www.asno.dfat.gov.au/nnr_technical.html Also, there's also some interesting anti-proliferation thorium breeders out there (which convert thorium to U233, which is fissile), such as the Radkowsky design. In short, there's a lot of neat stuff on the horizon.:)